I actually purchased this for use with "Call of Cthulhu" and it is perfect for that game. It is easily able to serve as the archetypal archeology "dig," or the secret lab buried out beyond the old Curwen Farm, or even, in a pinch, some handy ghoul tunnels beneath the rotting, gambrel-roofed houses of ancient Arkham. Be warned though -- this is not a standard CoC supplement -- it's simply a set of maps and layouts with places for you to note things and describe the rooms, halls and tunnels in more detail. It's a major time saver for the Keeper that needs something now and doesn't have a lot of time to make it up himself, but it will still require some work to be useful.
The production quality of the product was outstanding, and the reproduction quality from DriveThru RPG was excellent. I actually purchased this as part of a "bundle" including "Vampire Lair," and "Sinister Ruins." Of the three products, this one was the best for my purposes, though all were well done and potentially useful. Overall, I rate the "Barrow Tomb" as a solid five.